Margaret m



Oct. 22, 1929. A. LAUGHLIN, JR

METHOD AND ARTICLE FOR THE MANUFACTURE OF TUBES Filed Nov. 15, 1923 I I f HIIIIIHW IN/ENTOR Maw (Mn Patented Oct. 22, 1929 PATENT OFFlCE ALEXANDER LAUGHLIN, JR., OF EDGEWORTH, PENNSYLVANIA; MARGARET lvI. LAUGH- LIN AND THE UNION TRUST CO. OF PITTSBURGH, EXEGUTORS 0F SAID ALEXAN- DER LAUGI-ILIN, JR., DECEASED, ASSIGNORS TO CENTRAL TUBE COMEANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF IENNSYLVANIA METHOD AND ARTICLE FOR THE MANUFACTURE OF TUBES Application filed November 15, 1923.

The present invention relates broadly to the manufacture of tubes or pipes, and more particularly to the manufacture of so-called butt welded tubes.

At the present time it is customary to form tubes of the character herein contemplated from substantially flat strip or skelp in comparatively short lengths by first heating the same to the required temperature and thereafter passing the heated strip between suitable forming means for gradually bringing the heated edges together under welding pressure for effecting the weld, the strips being drawn through the forming means under great tension.

The use of rolls for forming the skelp is preferable to the use of bells and dies, but such rolls have heretofore not been possible due to the difficulty of initiating movement of the heated strip between the rolls. This, coupled with the short lengths in which the skelp has necessarily been handled, has prevented the successful use of such rolls.

In some special cases where rolls for tube making are being used, in order to enable the skelp to be entered into the first roll pass, a complete length of tube has been moved backwardly through the furnace and welded to the entering end of a piece of skelp. This not only requires the use of a finished section of tube, but involves a welding operation.

In accordance with the present invention, the difficulties encountered as before set forth are entirely obviated, and the manufacture of tube from strip material with the use of rolls in place of the usual draw bench is expedited. In this manner all drawing strain on the tubes is eliminated.

In the accompanying drawings, there are illustrated, more or less diagrammatically, two forms of apparatus in accordance with the present invention, it being understood that the drawings do not define the limits of my invention, as changes may obviously be made in the construction and operation disclosed therein without departing from the spirit of my invention or scope of my broader claims.

In the drawings:

Figure 1 is a view, partly in section and Serial No. 674,844.

partly in side elevation, of one form of heating furnace and drawing apparatus;

Figure 2 is a view similar to Figure 1, illustrating a modified form of furnace;

Figure 3 is a detail View of one form of a strip constructed in accordance with the present invention, and

Figure & is a sectional view on the line IVIV of Figure 3 looking in the direction of the arrows.

In accordance with the present invention, there may be provided a suitable furnace 2 adapted to support therein a coil 3 of strip material from which a tube or pipe is to be formed, the furnace being heated in any desired manner, as understood in the art. By heating the material in coil form, much greater lengths of material may be handled.

Cooperating with the furnace is a drawing and shaping apparatus, which may be of any desired construction, but which preferably comprises a plurality of pairs of rolls 4 adapted to successively act on portions of a strip heated within the furnace 2, and effect a weld between the heated edges thereof. The use of rolls, in place of dies and bells, is made possible partly in view of the greater lengths in which the material is handled and partly by reason of the pro-shaping of one end of the strip, as hereinafter more fully disclosed.

In Figure 2 there is illustrated a slightly modified form of furnace 2 adapted to support therein a substantially flat strip of material 3 from which a tube is to be formed. Cooperating with the furnace is a forming and welding apparatus comprising a plurality of pairs of rolls 4 similar to that already described.

In the manufacture of tubing, it is customary to place the material to be heated within a furnace and subject the same to a source of heat for sufficient time to bring the edges of the strip to, or substantially to, welding temperature. is grasped by an operative in suitable tongs and passed to a draw bench for drawing it through shaping and welding dies or bells. It will be apparent however that such an operation imposes a tremendous strain on the metal,

Thereafter, one end of the strip U the strain increasing with the length of the tube being formed. In accordance with the preferred embodiment of my invention, I eliminate the draw bench entirely and substitute a plurality of forming and welding rolls, as described. Obviously, however, the shape of the strip as heated is ordinarily not such as to permit the entry of the end between the first set of rolls. In order to overcome this difficulty and thereby make the use of rolls practicable, I provide each strip with one end preshapcd or pre-formed to facilitate its passage into and between the first set of rolls. In Figures 3 and 4 there is indicated a portion of a strip of material S having the edges at one end bent inwardly to provide a substantially circular cross section at this portion, this cross section preferably being similar to the cross section of the roll pass which the strip lirstenters in the welding operation. If desired, the meeting edges of the strip at this end may be welded to provide a substantially finished tube, whereby the production of a scrap end is obviated.

In View of the comparatively great lengths of tubes which may be produced in accordance with this invention, it wiii be apparent that the cost of the preshaping more than offset by the increased production and decrease in the percentage of scrap.

The method of heating a strip in coil form, as herein illustrated, is disclosed and claimed in my copending application Serial No. 674-,Ssi3, filed of even date herewith.

It will be apparent that by providing a strip having a pre-formed end as herein set forth, it is possible, after heating the strip either in flat or coil form, to easily introduce the pro-formed end into the first pass of the forming means herein illustrated as coirprising a pair of rolls 4% or i. This greatly expedites the starting of the actual tube forming operation, thereby enabling a strip which has been brought to welding temperature within the furnace to be more quicklyformed into a finished product, and drawn outwardly entirely by the operation of the forming means.

I claim: 7

1. In the manufacture of tubing, the steps comprising shaping one end only of a strip to an extent to prevent substantial deformation at welding heat to facilitate passage thereof into the tube forming means, thereafter heating the strip to a welding temperature, and then passing said shaped end to a roll forming and welding means and gripping the same by the forming means for withdrawing the strip from the source of heat.

2. In the manufacture of tubing, the steps comprising shaping one end only of a strip by bending the edges thereof inwardly, thereafter heating the strip to a welding temperature, and then introducing said shaped end into a forming and welding means and grip ping the same by the roll forming means for withdrawing the strip from the source of heat.

3. In the manufactureof tubing, the steps comprising forming a strip having one end only thereof shaped to substantially finished form, thereafter heating the strip, and then introducing said formed'e'nd into aroll formmeans and'gr'ipping the same by the nnprising a plurality of superimposed" windings in overlapping protecting relationship, thereafter heating the coil, and then introducing the shaped end into a roll pass between rolls of a tube-formii-ig means.

6. In the manufacture of tubing, the steps comprising shaping one end of a coiled strip on f luraiity of superimposed windin or... -apping protecting relationshlp by bending the edges thereof inwardly,

eafter heating the coil, and then introi the shaped end into a tube-forming 7'. In the manufacture of tubing, the steps comp ng shaping one end of a coiled strip sin a philrahty of supernnposed windir in overlapping protecting relationship by bending the edges thereof inwardly to substantially circular shape, thereafter heating the coil, and then introducing the shaped end into a tube-forming means.

In testimony whereof I have hereunto set my hand.

ALEXANDER LAUGHLIN, JR. 

